Elevated expression levels of the protein kinase DYRK1B induce mesenchymal features in A549 lung cancer cells.

Background: The protein kinase DYRK1B is a negative regulator of cell proliferation but has been found to be overexpressed in diverse human solid cancers. While DYRK1B is recognized to promote cell survival and adaption to stressful conditions, the consequences of elevated DYRK1B levels in cancer cells are largely uncharted.

Methods: To elucidate the role of DYRK1B in cancer cells, we established a A549 lung adenocarcinoma cell model featuring conditional overexpression of DYRK1B. This system was used to characterize the impact of heightened DYRK1B levels on gene expression and to monitor phenotypic and functional changes.

Results: A549 cells with induced overexpression of wild type DYRK1B acquired a mesenchymal cell morphology with diminished cell-cell contacts and a reorganization of the pericellular actin cytoskeleton into stress fibers. This transition was not observed in cells overexpressing a catalytically impaired DYRK1B variant. The phenotypic changes were associated with increased expression of the transcription factors SNAIL and SLUG, which are core regulators of epithelial mesenchymal transition (EMT). Further profiling of DYRK1B-overexpressing cells revealed transcriptional changes that are characteristic for the mesenchymal conversion of epithelial cells, including the upregulation of genes that are related to cancer cell invasion and metastasis. Functionally, DYRK1B overexpression enhanced the migratory capacity of A549 cells in a wound healing assay.

Conclusions: The present data identify DYRK1B as a regulator of phenotypic plasticity in A549 cells. Increased expression of DYRK1B induces mesenchymal traits in A549 lung adenocarcinoma cells.